Surf is building along California's coast. The National Weather Service issued a high surf advisory Wednesday for beaches stretching from Half Moon Bay to Big Sur.

Waves just to the north and south of San Francisco could hit 20 feet, while sets topping 18 feet are expected along the Central Coast. Waves from 8 feet to 12 feet are predicted from Los Angeles to San Diego.

According to swell forecasting website Surfline.com, surf will remain high through Saturday night.